It's incredible to see how much 'Doom' has changed in 20 years

To say that "Doom" is one of the most important games in history is an understatement. When it came out in 1993, it changed the course of the games industry, ushering in an era of quick and dirty first-person shooters — in fact, before the term "first-person shooter" became popularized, they were simply called "Doom clones."

Those abs! YouTube/JD Rock

Despite the importance of the original "Doom," there's no doubt that games have changed a lot since 1993. Given the impending release of the newest "Doom" on May 13, we put together a look back at just how much the visuals of the series have advanced over the past 20 years.